Drug reference

Mefloquine

Antimalarial

AntimalarialATC null

CDSCO approvedSchedule H

EXCRETION

—

not curated

INTERACTIONS

12 major

SEVERE in our sources

PREGNANCY

Avoid in first trimester; use only if no alternative in 2nd/3rd trimester

FDA category + note

Top interactionssee all 12 →

Beta Adrenergic BlockersSevereTextbookHarrison 22e · p1744, p1749
AmiodaroneSevereDatabaseDDInter
AmisulprideSevereDatabaseDDInter
AnagrelideSevereDatabaseDDInter

Mechanism

Mefloquine is a quinoline methanol blood schizonticide structurally related to quinine that kills erythrocytic-stage Plasmodium by accumulating in parasite food vacuoles and inhibiting heme polymerization, similar to chloroquine. However, its distinct chemical structure maintains activity against chloroquine-resistant strains. Mefloquine's long elimination half-life (2-3 weeks) enables weekly prophylactic dosing but also means adverse neuropsychiatric effects (vivid dreams, anxiety, psychosis) may persist for weeks after discontinuation.

Indications

Prophylaxis of malaria in areas of chloroquine resistanceTreatment of acute, uncomplicated falciparum malariaTreatment of non-falciparum malariaprevention and treatment of malaria caused by known or suspected drug-resistant p. falciparum and p. vivaxchemoprophylaxis for travelerscombined with artemisinin compoundsMalaria (prophylaxis for travellers to endemic areas with high transmission rate)multidrug resistant P. falciparumuncomplicated falciparum malaria (in combination with artesunate as ACT)P. vivax malaria (in rare cases resistant to both chloroquine and quinine+doxycycline)prophylaxis of malaria (for travellers to areas with multidrug resistance)

Dosing

Adult: Treatment: 1250 mg as a single dose or 750 mg then 500 mg 6-8h later. Prophylaxis: 250 mg weekly, start 2-3 weeks before travel, continue 4 weeks after return.
Pediatric: Chemoprophylaxis: ≤9 kg: 4.6 mg/kg base (5 mg/kg salt) orally, once/week; >9–19 kg: 1/4 tab weekly; >19–30 kg: 1/2 tab weekly; >31–45 kg: 3/4 tab weekly; ≥45 kg: 1 tablet weekly. Treatment: 13.7 mg base/kg (15 mg salt/kg) orally as initial dose, followed by 9.1 mg base/kg (10 mg salt/kg) orally given 6–12 h after initial dose (Total dose = 25 mg salt/kg).

Pharmacokinetics

Onset

17 h (peak plasma levels)

Half-life

13–24 days

Bioavailability

—

Protein binding

~98% (plasma proteins)

Metabolism

extensively metabolized in the liver by cyp3a4

Excretion

<1%

Contraindications

Should not be used for treatment if it has been used for prophylaxis
Unsuitable for malaria prophylaxis in individuals with a history of epilepsy
allergy to mefloquine or related compounds (e.g., quinine, quinidine)
active depression
recent history of depression
generalized anxiety disorder
psychosis
schizophrenia
other major psychiatric disorders
seizures
cardiac conduction abnormalities
history of seizures
bipolar disorder
adverse reactions to quinoline antimalarials
p. falciparum infections acquired in thailand-burmese and thailand-cambodian border regions
western provinces of cambodia
eastern states of burma (myanmar)
border between burma and china
laos along borders of laos and burma (and adjacent parts of thailand-cambodia border)
southern vietnam
anxiety
depression
cardiac conduction defects
first trimester of pregnancy (unless absolutely essential)

Side effects

Common

vivid dreamsdisturbed sleepdysphoriaheadachegastrointestinal disturbancesdizzinessnauseavomitingdiarrhoeaabdominal painsinus bradycardiaq-t prolongationdisturbed sense of balanceataxiaerrors in operating machinerystrange dreamsanxietyhallucinationslightheadednessconfusionnightmaresinsomniavisual disturbancetransient and clinically silent ecg abnormalities (sinus bradycardia, sinus arrhythmia, first-degree av block, qt prolongation, abnormal t waves)

Serious